Keeping track of external sources is a key task of writing a research-based document. Users often perform research using sources available via the internet, for example, using a web browser. While researching, the user may review a large number of documents. If the user does not immediately write a citation for material that they incorporate into their research based document (e.g. by quoting), they may have difficulty later identifying the source in order to properly cite the source. For example, the user may forget from what source a particular quotation was derived, and subsequently be unable to find the original source again.